Paraovarian cysts associated with prenatal diethylstilbestrol exposure. Comparison of the human with a mouse model.

The association of prenatal exposure to diethylstilbestrol (DES) and abnormalities in structures of müllerian (paramesonephric) origin has been well documented. In a murine model, exposure to DES in utero results in persistent mesonephric remnants in adult female mice. Six women exposed prenatally to DES had paraovarian cysts excised during routine gynecologic surgery; and in 4, histologic abnormalities were observed, including thickened fibromuscular walls with tall columnar epithelium in a papillary or pseudoglandular configuration. Four of 25 nonexposed and 8 of 9 DES-exposed infertile women undergoing surgery for infertility had paraovarian cysts, and the difference was statistically significant (P less than 0.02). These findings raise the possibility that structures derived from the mesonephric ducts or tubules may also be affected in women exposed in utero to DES.